Hm… All information in the OSM database is hard-coded, and can be seen as rendering hint. If I enter information that I find important to an object, probably (hopefully) a map or app aimed at people who care about this sort of information will render it.
Now my understanding is that tiles are created with some, but not all, information included, so tile users can use the basic tiles, modify them, or even have the client side modify the style. Information in the tile differs from the OSM database. So I can understand that at the tile level one could make a difference between information that is used to pre-format the tiles, and information that is transformed and included in the tiles for later processing.
From the mapper’s point of view, this is a renderer’s decision. THe mapper just puts information in the database (probably dreaming a lot about the end result on a map, but the dreams are not captured, the information is).
Even osmc:symbol is nothing more than information. It’s not the symbol itself, but only a description, which is fortunate because our national hiking/foot/walking route operator wanted to sue us for illegal use of the route symbol (white-over-red, in license from the French, they told me). By the way, that is also why we can’t use pictures for the route symbols: that would be illegal copying and distribution of a licensed trade mark).